Recently a bag-type tampon has been introduced which has some novel characteristics. This tampon described in U.S. Pat. No. 3,815,601 utilizes a fluid-permeable outerwrap and discrete pieces of a compressible foam dispersed therein.
Additional highly absorbent particulate material is mixed in with the foam pieces in the bag to increase the absorptive capacity of the tampon. This is done because the foam pieces do not retain large amounts of fluid and the flexing of the vaginal walls associated with bodily movement tends to squeeze retained fluid out of the interior of the foam.
Tampons of this type are made by filling the porous bag with the absorbent particles and foam, compressing the bag by inserting the tampon in a conventional telescoping inserter. After vaginal insertion, the tampon resumes its original configuration due to the "springing back" of the compressed foam to its original contours. The bag in its original configuration presses against the vaginal walls to prevent leakage around the tampon edges.
While this particular configuration does tend to prevent leakage it makes "dry removal" difficult. If the tampon is removed before substantial flow the bulk of the tampon causes removal difficulties even with compressibility of the foam. The subject invention provides a bag-type tampon and a method for its assembly which overcomes many of the difficulties encountered with the above-mentioned bag-type tampon by utilizing a different absorbent system, and a different manner of assembly.
Superabsorbents or hydrogels as absorptive materials have also been used for tampons. They may produce discomfort for the tampon wearer however. These materials have a strong affinity for fluid, so strong that they produce a suction phenomenon at the surface of the tampon where it contacts the vaginal walls. Removal of the tampon, therefore, produces a shearing force at the surface interface between the vagina and the bag.